A TOUR ROUND NORTH WALES. 173 



little arches in their work, and fixing the 

 reft of the wall upon them. At Segon- 

 tium this appears to me to have been by 

 no means the cafe, for the holes are too 

 fmall, and at by far too great a diftance 

 from each other to have been of any ma- 

 terial ufe in taking off from the weight: 

 and for my own part, if I may be allowed 



i 



a conjecture, merely from their external 

 appearance, I mould be inclined to fup- 

 pofe, notwithftanding the circumftance of 

 their being faid to be found below the 

 natural furface of the ground at Manchef- 

 ter, that they were made for no other 

 purpofe than merely to place in them 

 poles for refling the fcaffolding upon, ufed 

 in conftrudting the walls, and they may 

 probably have been left unfilled up in 

 order to admit the air into the interior of 

 the work, or for fome other purpofe, with 

 which I am not acquainted. I am more 

 inclined to this conjecture, fince they are 



all 



